Liquid fuel injectors



July 9, 1957 J. w. wHlTsoN LIQUID FUEL INJECTORS Filed Sept. 27, 195

`Patented July 9, 1957 2,798,769 LQUID FUEL INJECToRs John W. Whitson,New York, N. Y., assignor of one-half to Mrs. Clare H. Whitson, NewYork, N. Y.

Application September 27, 1956, Serial No. 612,398 '26 claims. (Cl.299-1016) With the above mentioned and other objects in view, r

the invention consists in the novel construction and combination ofparts hereinafter described, illustrated in the l accompanying drawings,and set forth in the claims hereto appended, it being understood thatvarious changes in form, proportion, size, location and minor details ofconstruction within the scope of the claims may be resorted to withoutdeparting from the spirit or sacrificing any of t the advantages of theinvention.

Referring to the drawings: Fig. 1 is a sectional view through a liquidfuel injector.

Fig. 2 is a sectional view through some of the elements of the injectorillustrated in Fig. l.

Fig. 3 is a wiring diagram illustrating the electrical control systemfor the injectors illustrated in Figs. l and 4.

Fig. 4 is a sectional view through a liquid fuel injector.

Fig. 5 is a sectional view through a liquid fuel injector.

Fig. 6 is a wiring diagram illustrating the electrical control systemfor the injector illustrated in Fig. 5.

Fig. 7 is a sectional view through a liquid fuel injector.

Fig. 8 is a wiring diagram illustrating the electrical control systemfor the injector illustrated in Fig. 7.

Fig. 9 is a sectional View through a liquid fuel injector.

Fig. 10 is a wiring diagram illustrating the electrical control systemfor the injector illustrated in Fig. 9.

Fig. 11 is a wiring diagram illustrating an electrical control system.

Fig. l2 illustrates the cycle ternal combustion engine.

Fig. 13 is a sectional view through a liquid 'fuel injector. j

In detail the construction illustrated in the drawings comprises anouter injector casing 1 as illustrated in Fig. l composed of twosections of non-magnetic material joined together by a plug member 2,made of magnetically conductive material; the plug 2 divides the casinginto fuel chambers 3 and 4 which are connected bythe opening 5 in theplug.

Chamber 3 is closed at its outer end by the plug 6 which is threaded toreceive the fuel line 'i which is connected to a source of liquid fuelsupply.

curve of a four cycle in- Chamber 4 is closed at its outer end by thecap 8 t.

which is threaded to receive the casing 1 and threaded as at 9 forscrewing into an opening leading into a com bustion space C in whichliquidfuel is to be burned.

Cap 8 has an orifice 10 in which needle valve 11 is seated by spring 12.

Plug 6 has an opening 13 therethrough in which needle valve 14 is seatedby spring 15.

Needle valves 11 and 14 each have `grooves 16 and 17 formed in theirenlarged portions to allow for the free V ilow of the fuel in thechambers 3 and 4.

A boss 18 on the casing 1 has a tapped hole provided to receive thevolume adjusting screw 19 which is provided with a lock nut 20.

Solenoid coils 21 and 22 are secured to the casing 1 and are providedwith a casing 23 composed of iron-impregnated plastic or other suitablemagnetically conductive material. The solenoid coils are connected to anelectrical timer and a source of electrical energy.

Fig. 2 illustrates the functioning `of the solenoids; the dotted lines Fand F linx in the solenoids when they are energized. The needle valves11 and 14 function as the movablecores of the solenoids and they areattracted to the plug 2, when the solenoids are energized, to close thegaps G and G; the closing of the gaps serves to unseat the needlevalves; the needle valves are reseated by the springs 12 and 15 when thesolenoids are de-energized.

Fig. 3 illustrates a source of electrical energy 100 connected tosolenoid coils 21 and 22 by wire 101 and to a timer 102 by wire 103;wires 104 and 105 connect the timer brushes to the coils 21 and 22.

Uperation With the chambers 3 and 4 of Fig. l filled with fuel at normaldensity and with an assumed density that would be equal substantially to3000 pounds per square inch pressure on the fuel in the fuel line 7;then when the timer 102 is cycled, solenoid coil 21 will be energizedto` unseat needle valve 14 to permit fuel to flow into fuel chamber 3and raise the density of the fuel in chambers 3 and 4 to the density ofthe fuel in fuel line 7.

The amount of fuel that will enter chamber 3 will approximate 1% of thevolume of the fuel in the chambers 3 and 4 when the fuel was at normaldensity, assuming that the modulus of elasticity of the fuelapproximates that of water.

Experiments show that the alteration in volume of liquids isproportional to the density, hence the relation between the changes ofvolume when under pressure may be expressed:

Then i v P pV rrr of. K T

K=from 320,000 to 300,000 pounds per square inch. Thus the water isreduced in bulk or increased in density by 1% when under a pressure of3000 pounds per square inch. This is quite apart from the strech of thecontaining vessel.

When coil 21 is de-energized needle valve 14 is reseated by the spring15, sealing the fuel in fuel line 7 against entry into chamber 3.

Solenoid coil 22 is next energized to unseat needle valve 11 and permitthe release of substantially 1% of the fuel through the orice 10 wichdrops the density back to normal on the fuel remaining in the fuelchambers.

When coil 22 is de-energized needle valve 11 is reanother cycle.

indicate the path of the magneticl 3 Thus theinjector is self-meteringasto successive fuel charges and can be throttled by varying the pressureon the fuel in the fuel supply line.

A pressure of =1'500poundsfper`square inch on'f the fuel will pass onehalf of the amount f fuel into'chamber'l,y

as compared to a pressurevof'3000' pounds,;6000 pounds will pass twiceas much fuel. 1

In the manufacture of .a series ofinjectors differences inthe volumes ofthe fuel: chambers 3 and .4' may occur, in which event the volumeadjustingr screw 19 'willbe positioned to normalize the volumeof thefuel chambers.

Fig, 4- illustrates an injector withA its fuel chamber 3 having an openconnection to theifuel line v7 and with the positionolthe needlecvalve14f1reversed` fronrfthat illustrated in Figure lso vas to. seat in: theopening '5*y of plug 2.to'. seal chamber 4 fromV chamber 3 and from thefuel'supply.

Solenoid coil..21is.moved so that plug which is `made offmagneticallyattractiveimaterial serves as an element of the:solenoid to Vattractandv unseat theneedle valve 14 whenqcoili 21 is energized.

Operation With chamber 4 of Fig. 4 lled with fuel at normal density andwith fuel of greater density in chamber 3 then, when coil 2l isenergized, needle valve 14 will be attracted to plug 6 and unseat topermit fuel to flow into chamber 4 and raise the density of thefueltherein to the density of the fuel in chamber 3; when coil 2l isde-energized needle valve 14 will be reseated; solenoid coil 22 is nextenergized and the action then follows that is described for theoperation of the injector illustrated in Fig. l.

Fig. illustrates an injector which is also provided with solenoids tocontrol the seating of its needlevalves.

Casing 1 is divided into two fuel chambers 3a and 4a by plug 24 whichhas an opening 25 therethrough inl one-end of which is seated needlevalve 14a which has a stem 26 that extends through the opening 27 inplug 2a which is similar tol plug 2 of Fig. 1; a movable sole-Y noidcore 28 bears against the stern 26 to maintain needle valve 14a seatedwhen coil 33 is energized.

Needle valve 11a is similar to needle valve 11 of Fig. 1 and has a stem29 which extends through the opening 30 in plug'Za which is similar toplug 2 of Fig. l; a movable solenoid coil 31 bears against the stem 29to maintain the needlevalve 11a seated when coill 36 is energized.

Needlel valve 14a is closed and opened by the solenoid coils 33 'andl 34which are provided with a casing 35 composed of magnetically conductivematerial. Solenoid coils 35-and 37 serve to close and open the needleValve 11a.

Fig. 6 illustrates a source of electrical energy 200 connected tosolenoid coils 33, 34, 36 and 37 by `wire 201 and to a'timer 202 by wire203, wires 204 connect the timer brushes to the solenoids.

The timer will cycle to energize coil 33 to maintain needle valve 14aseated; to energize coil 34 to unseat needle valve 14a; to energize coil36 to maintain needle valve 11a seated; and to energize coil 37 tounseat needle valve 11a.

Operation With the chamber- 4a of Fig. 5 filled with fuel at ynormaldensity and with chamber3a supplied with fuel of a greater density andwith the timer 202 positioned toenergize coils 33 and 36, then a cycleofthe timer-will first de-energize coil 33 andenergize coil 34 to unseat.needle` valve l4a to permit fuel to enter chamber 4a toA increase the`density of the fuel in chamber 4a to equal the density Vofthe fuel inchamber 3a, coil 34is then cle-energized and coil 33 is energizedto seatneedlevalve 14a andsealk the fuel chamber 4a; next coil 36visde-energizedand coil 37 is energized to unseat needle valve 11a andpermit the dischargeof fuel .through the orice coil .37.isthende-'energized and coill 36 is energized to unseat needle.y

valve 11a, completing a cycle of the timer.

Fig.` 7 illustrates an injector similar to the injector illustrated inFig. l except that the fuel chamber 3 and its elements are not included.Plug 6b is similar to plug 6 of Fig. 1. The portion of the needle valve11b which serves as the movable core of solenoid coil 2lb has beenshortened to provide space for the check valve 38 which also serves aspart of the movable core of the solenoid. The check valve contains aball 39 whichV seats in the opening 13b to seal chamber 4 "againstVentry of fuel from fuel line 7 when coil 2lb is energized. The coil 2lbis encased in magnetically conductive material.

Fig. 8 illustrates a source of electrical energy 300 connected to thesolenoid coil 2lb by wire 301 and to a timer 302 by wire 303;` the timeris connected to-'coil 2lb by wire 304.

Operation With fuel chamber 4 of Fig. 7 containing fuel under pressurefrom fuel line 7, then when the timer 302 cycles to energize coil 2lb,check valve 38 will be attracted by plug 6b` and seat ball 39 tightly inthe opening 13b to seal olf the fuel in chamber 4 from the fuel supplylin line 7; needle valve 11b will be attracted against check valve 38unseating the needle valveto permit the discharge of fuel through theorifice 10; when coil 2lb is de-energized spring 12b will reseat theneedle valve and de-energizing coil 2lb will also release the checkvalve so that fuel can enter chamber 4 from fuel line 7, completing thecycle of the timer.

The pressure of spring 12b against the needle valve 11b delays itsunseating until after the check valve has sealed the opening 13b Fig. 9illustrates an injector similar to that illustrated in Fig. 5 exceptthat the fuel chamber 3a and its elements are not included and plug 6serves to close fuel chamber 4a. Fuel chamber 4a and its elements aresimilar to those illustrated in Fig. 5 and function in a like manner.

Fig. 10 illustrates a source of electrical energy 400 connected to coils36a and 37a by wire 401 and to a timer 402 by wire 403, wires 404connect the timer brushes to the coils.

Operation While the fuel line 7 connected to a metering fuel pump thatdelivers fuel under pressure into fuel line 7 and thence into fuelchamber 4a and with the timer 402 positioned to energize coil 36a then acycle of the timer will first deenergize coil 36a and energize coil 37ato unseat needle valve 11a to permit fuel to discharge through theorifice 10; the volume of the discharge will be as determined by thefuel pump, and the cycling of the fuel pump and the timer can becoordinated so that the fuel will be under substantial pressure at lthetime of discharge; coil 37a will be de-energized and coil 36a energizedto reseat the needle valve 11a, preparing the injector for anothercycle.

Any of the injectors illustrated can be used toinject engine in eitherthe Otto or Diesel cycles.

The same injector can also be used to inject fuel in either the Otto orDiesel cycles in the same engine so that an engine using a vaporizingfuel may have fuel injected during the intake stroke in the Otto cycleto warm up the engine and then when the engine is warm it may beswitched to inject fuel during the compression stroke in the Dieselcycle.

The enginecan operate in the Otto cycle for maximum power output at fullthrottle and then be switched to the Diesel cycle for maximum economywhenv operating at less than full throttle; this feature can be utilizedin aircraft engines; the Otto cycle providing thev maximum powernecessary to get the plain airborne and the Diesel cycle providingeconomical power Vto cruise the plane when it is airborne.

Fig. 1l illustrates how a timer can be-'arrangedy to operate theinjector of Fig.. 7 in.l either thegrOtto or'Diesel cycles.

A source of electrical energy 500 is connected to coil 2lb by wire 561and to a timer 502 by wire 503, a switch 504 serves to connect coil 2lbto either of the timer brushes 505 or 506.

In a four cycle engine the timer will operate at one half of the enginespeed, then, with the switch 504 closing the circuit of brush 505, theinjector will cycle to inject fuel during the intake stroke of theengine and when the switch closes the circuit of brush 506 the injectorwill cycle to inject fuel during the` compression stroke of the enginein accordance with the diagram of Fig. 12 in which line 600 representsthe cycle curve of a four cycle internal combustion engine and 601represents the point at which injection starts during the intake strokein the Otto cycle and 602 represents the point at whichinjection startsduring the compression stroke in the Diesel cycle.

My invention provides a method for operating liquid fuel injectors whichutilizes the theory of the compressibility of liquids for metering thefuel charges and injecting them into a combustion chamber, a newdiscovery in this art.

Fig. 13 illustrates an injector which is a modification of thosepreviously illustrated. The injector comprises a cruciform casing 1cenclosing two fuel chambers 3c and 4c which have functions similar tothose `of chambers 3 and 4 of Fig. 4; needle valves 11e and 14e seat inorifice and opening 38 of plug 39 respectively and the upper ends of theneedle valves are cone-shaped as at 40 and each needle valve has aspring 41 which tends to unseat the valve and causes the valve to bearagainst the coneshaped ends 40 of the movable elements 42 which areiniluenced to move away from each other by the springs 43; each of theelements 42 has a stem 43 which extends through the opening 44 in a plug45 and abuts against the movable cores 46 of the solenoid coils 47 and47 which are similar to the solenoid coils described herein; plugs 48seal the chambers 3c and 4c, and chamber 3c is also sealed by plug 6into which fuel line 7 is threaded. The casing 1c is made ofnon-magnetic material; the other parts are made of magneticallyattractive materials.

Operation With the chamber 4c filled with fuel -at normal density andwith fuel of greater density in chamber 3c and with the coils 47 and 47energized the needle valves llc and 14e will be maintained seatedsealing chamber 3c from chamber 4c and chamber 4c against the dischargeof fuel through orifice 1l); when coils 47 are de-energized the spring43 will force the movable elements 42 apart and the spring 41 willunseat the needle valve 14e to permit fuel to ilow into chamber 4c andraise the density of the fuel therein to the density of the fuel inchamber 3c; coils 47 are then energized to seat valve 14e and sealchamber 4c; coils 47 are then de-energized to unseat needle valve 11e(as described for needle valve 14e) for fuel to discharge throughorifice 10 and reduce the fuel remaining in the chamber 4c to normaldensity; coils 47 are then energized to seat needle valve 11e.

The springs 43 may be omitted and `the elements 42 moved with thesolenoids arranged like those of Figs. 4, 5, and 9. With high densityfuel the springs 41 may be omitted as the high density fuel will tend tounseat the needle valves when the elements 42 are moved from theirobstructing positions.

Leakage of fuel when under high pressure has been a poor quality featureof fuel injectors designed to meter and inject fuel `in mechanical timewith the engine cycle; my injector overcomes this as its movableelements are completely sealed within the injector casing and do notrequire outside mechanical connections to operate them, since they areoperated through the instrumentality of magnetic attraction, a newdiscovery in this art.

My invention provides for utilizing electro-mechanical devices to timethe injection cycle, a new discovery in this art.

The drawings do not show construction details such as' removable seatsfor the needle valves, a nozzle tip for orifice 10, etc., as would bethe case in commercial designs; only the elements necessary to disclosethe invention are shown so that the relationship of the common elements,of the several injectors illustrated, may be clearly seen.

While the above describes the injectors as operated with liquid fuel itis to be understood that they will operate with matter in a lluid statewhether liquid or gaseous.

When the term normal density is used it may also mean the density atatmospheric pressure.

Having described my invention above in detail I wish it to be understoodclearly that many changes may be made therein without departing from thespirit of the same.

I claim:

l. The method of operating an injector having a lluid chambercomprising: sealing the chamber against the discharge of fluid; fillingthe chamber with iluid at normal density; unsealing the chamber fortluid to enter and increase the density of the liuid contained thereinabove its normal density; sealing the chamber, with the iiuid containedtherein at the increased density; then unsealing the chamber for aportion of the iiuid to discharge therefrom and reduce the iluidremaining in the chamber to normal density.

2. The method of loperating an injector having a fluid chambercomprising: sealing the chamber against the discharge of lluid; fillingthe chamber with fluid at normal density; unsealing the chamber, throughthe instrumentality of magnetic attraction, for iluid to enter andincrease the density of the fluid contained therein above its normaldensity; sealing the chamber, with the fluid contained therein at theincreased density; then unsealing the chamber, through theinstrumentality of magnetic attraction, for a portion of the iiuid todischarge therefrom and reduce the iluid remaining in the chamber tonormal density.

3. The method of operating an injector having a liuid chambercomprising: sealing the chamber, through the instrumentality of magneticattraction, against the discharge of fluid; unsealing the chamber forduid to enter and increase the density `of the iiuid contained thereinabove its normal density; sealing the chamber, through theinstrumentality of magnetic attraction, withthe iluid contained thereinat the increased density; then unsealing the chamber for a portion ofthe fluid to discharge therefrom and reduce the density of the fluidremaining in the ychamber to normal density.

4. The method of operating an injector having a iiuid chambercomprising: sealing the chamber through the instrumentality of magneticattraction, against the discharge of liuid; lilling the chamber withfluid at normal density; unsealing the chamber, through theinstrumentality of magnetic attraction, for the tluid to enter andincrease the density of the fluid contained therein above its normaldensity; sealing the chamber, through the instrumentality of magneticattraction, with the lluid contained therein at the increased density;then unsealing the chamber, through the instrumentality of magneticattraction, for a portion of the fluid to discharge therei from andreduce the lluid remaining in the chamber to normal density.

5. The method of operating an injector having a fluid chambercomprising: sealing the chamber against the discharge of fluid; lillingthe chamber with iiuid at above normal density, While maintaining the`chamber sealed against the discharge of the fluid; then unsealing thechamber for a portion of the liuid to discharge therefrom and reduce thefluid remaining in the chamber to normal density.

6. The method of operating an injector having a lluid chambercomprising: sealing the chamber against the discharge of luid; fillingthe chamber with fluid above normal density, while maintaining thechamber` sealed avea-veo against '.the. discharge of the fluid; thenunsealing the chamber, through the instrumentality of magneticattraction, fora portion of the fluid to discharge therefrom and reducethe fluid remaining in the chamber to normal density.

7. Th'emethod of operating an injector having a fluid chambercomprising: sealing the chamber, through the instrumentality of magneticattraction, against the discharge of fluid; filling the chamber withfluid above normal density, While maintaining the chamber sealed againstthe discharge of fluid; then unsealing the chamber, through theinstrumentality of'magnetic attraction, for a portion of the fluid todischarge therefrom and reduce the fluid remaining inthe chamber'tonormal'density.

8. The method Iof operating an injector having a fluid chambercomprising: sealing the chamber against the discharge offluid; fillingthe chamber with fluid at normal density; subjecting the fluid to asource of pressure to increase its density above normal density; sealingthe chamber and the fluid contained therein from the source of pressure;then unsealing the chamber for a portion of the fluid to dischargetherefrom and reduce the lluid remaining in the chamber to normaldensity.

9. The method of'operating an injector having a fluid chambercomprising: sealing the chamber against the discharge of fluid; fillingthe chamber with fluid at normal density; subjecting the fluid'to asource of pressure to increase its density above normal density; sealingthe chamber and the fluid contained `therein from the source ofpressure; then unsealing the chamber, through the instrumentality 'ofmagnetic attraction, for a portion of the fluid 'to discharge therefromand reduce the fluid remaining in the chamber to normal density.

10. The method of operating an injector having a fluid chambercomprising: sealing the chamber, through the instrumentality fofmagnetic attraction, against the discharge of fluid; filling the chamberwith fluid at normal density; subjecting the fluid to a source ofpressure to increase its density above normaljdensity; sealing thechamber :and the lluidcontainedtherein from the source of pressure; thenunsealing the chamber for a portion of the fluid to discharge therefromand reduce the fluid remaining in the chamber to normal density.

ll. The method of operating an injector having a fluidchambercomprising: sealing the chamber, through the instrumentality ofmagnetic attraction, against the discharge of'fluid; filling the chamberWith fluid at normal density; subjecting the fluid to a source ofpressure to increase its density above normal density; sealing thechamber and the fluid contained therein from the source of pressure,through the instrumentality' of magnetic attraction; then unsealing thechamber, through the instrumentality of magnetic attraction, for aportion of the fluid to discharge therefrom and reduce the fluidremaining in the chamber to normal density.

12. The method of operating an injector having a fluid chambercomprising: sealing the chamber against the discharge of fluid; fillingthe chamber with fluid at normal density; subjecting the fluid to asource of pressure to increase its density above normal density Whilemaintaining thechamber sealed; then unsealing the chamber for a portionof the fluid to discharge therefrom and reduce the fluid remaining inthe chamber to normal density.

13. The method of operatingf an injector having a fluid chambercomprising: sealing the chamber against the dischargeof fluid;subjecting the fluid to a source of pressure to' increase its densityabove normal density, While maintaining the chamber sealed; thenunsealing the chamber, though the instrumentality of magneticattraction, for aportion of the fluid to discharge therefrom and ,reducethe fluid remaining in the chamber to normal density.

14: The method of operating, an injector having a fluid chambercomprising: sealing the chamber, through the instrumentalityof magneticattraction, against the dischargeof-lluid; subjecting 'thelluid'to asource of pressure to increase its density above normal density; then'unsealing the chamber, through the instrumentality of magneticattraction, for a portion of the fluid to discharge therefrom and reducethe remaining fluid in. thechamber to normal density.

15. A fluid injector comprising in combination: a chamber for thecontainment of fluid; means to fill the chamber with fluid above vnormaldensity; means to seal the chamber after it is filled with fluid abovenormal density, and means to unseal the chamber, when it is filled withfluid above normal density, fora portion of fluid above normal densityto discharge from the chamber which discharge reduces fluid remaining inthe chamber to normal density.

16.'A fluid injector comprising in combination: a chamber for thecontainment of fluid; means to ll the chamber with fluid above normaldensity; means to seal the chamber .after it is filled with fluid abovenormal density; means to unseal the chamber, When it is filled withfluid above normal density, for a portion of the fluid above normaldensity to discharge from the chamber whichV discharge reduces the fluidremaining in the chamber to normal density, and means to move` thesealing and unsealing means through the instrumentality of magneticattraction.

17. AV fluid injector comprising in combination: a chamber for thecontainment of fluid; means to fill the chamber with fluid above normaldensity; means to seal the chamber after it is filled with fluid abovenormal density; means to unseal the chamber, when it is filled withfluid above normal density, for a portion of the fluid above normaldensity to discharge from the charnber which discharge reduces the fluidremaining in the chamber to normal density, and means to move theunsealing, means through the instrumentality of magnetic attraction.

18. A fluid injector comprisingA in combination: a chamber for thecontainment of fluid; means to fill the chamber with fluid above normaldensity; means to seal the chamber after it is filled With fluid abovenormal density; means to unseal-the chamber, when it is filled withfluid above normal density, for a portion of the fluid above normaldensity to discharge fromthe chamber which discharge reduces the fluidremaining in the chamber to normal'density, andl means to` move thesealing means through the instrumentality of magnetic attraction.

19. AV fluid injector comprising in combination: a sealed vchambercontaining fluid at normal density; means to unseal the chamber for theentry of fluid above normal density which entry increases the density ofthe fluid in the chamber; means to seal the chamber after the entry offluid above normal density and means to unseal the chamber, when it islled with fluid above normal density,

for a portion of the fluid above normal density to discharge from thechamber which discharge reduces the uid remaining in the chamber tonormal density.

20. A fluid chamber comprising in combination: a sealed chambercontaining fluid at normal density; means to unseal the chamber for theentry of fluid above normal density which entry increases the density.of the fluid in the chamber; means to seal the chamber after the entryoffluid above normal density; means to vunseal the chamber, when it isfilled with fluid above normal density, for a portion of the fluid abovenormal density to discharge from the chamber which discharge reduces thefluid remaining in the chamber to normal density, and means to move thesealing and unsealing means through the instrumentality of magneticatraction.

21. A fluid chamber comprising in combination: a sealed chambercontaining fluid at normal density; means to unseal the chamber for theentry of fluid above normal density which entry increases the density ofthe fluid in the chamber; means to seal'the chamber after the entry offluid above normal density; means to unseal the chamber, when it is lledwith fluid above normal density, for a portion of the tluid above normaldensity to discharge ffrom the chamber which discharge reduces the iiuidremaining in the chamber to normal density, and means to move theunsealing means through the instrumentality of magnetic attraction.

22. A fluid injector comprising in combination: a sealed chambercontaining fluid at normal density; means to unseal the chamber for theentry of fluid above normal density which entry increases the density ofthe iluid in the chamber; means to seal the chamber after the entry ofthe fluid above normal density; means to unseal the chamber, when it islled with uid above normal density, for a portion of the above normaldensity tluid to discharge from the chamber which discharge reduces theuid remaining in the chamber to normal density, and means to move thesealing means through the instrumentality of magnetic attraction.

23. A uid injector comprising in combination: a chamber containing tluidabove normal density; means to seal the chamber against the discharge offluid above normal density, and means to unseal the chamber, when it ,isiilled with tluid above normal density, for a portion of .the fluidabove normal density to discharge from the chamber which dischargereduces the tluid remaining in the chamber to normal density.

24. A Huid injector comprising in combination: a chamber containingiluid above normal density; means to seal normal density,

the chamber against the discharge of duid above normal density; means tounseal'the chamber, when it isy filled vwith fluid above normal density,for a portion of the fluid above normal density to discharge from thechamber which discharge reduces the uid remaining in the chamber tonormal density, and means to move the sealing and unsealing meansthrough the instrumentality of magnetic attraction.

25. A fluid injector comprising in combination: a chamber containingHuid above normal density; means to seal the chamber against thedischarge of fluid above normal density; means to unseal the chamber,when it is filled with Huid above normal densit for a portion of theabove normal density fluid to discharge from the chamber` whichdischarge reduces the fluid remaining in the chamber to and means tomove the unsealing means through the instrumentality of magneticattraction.

26. A fluid injector comprising in combination: a charnber containingfluid above normal density; means to seal the chamber against thedischarge of iluid above normal density; means to unseal the chamber,when it is filled with iluid above normal density, for a portion of theiluid above normal density to discharge from the chamber which dischargereduces the iuid remaining in the chamber to normal density, and meansto move the sealing means through the instrumentality of magneticattraction.

No references cited.

